Laparoendoscopic single-site surgery (LESS) is the newest alternative to conventional multi-incision laparoscopic surgery. LESS offers improved cosmesis and may decrease postoperative pain and recovery time compared to conventional laparoscopy (CL) since the surgeon makes a single, small incision-typically within the patient's navel-in order to insert several instruments and a laparoscopic camera. In contrast to CL, the technical challenges of LESS stem from the fact that all of the instrumentation is inserted through a single 2-cm incision resulting in instrument collisions, an in-line view of the instruments, the surgeon's close proximity to assistants, and transposed instrument viewing (i.e., right instrument operates on the left side in monitor). Current compensatory practices aim to reduce the physical and/or cognitive load on the surgeon. However, they result in awkward postures and extreme wrist angles potentially resulting in discomfort and injury. Since various injuries, such as surgical fatigue, have become increasingly common among laparoscopic surgeons, these physical workarounds could lead to an increase in surgeon morbidity potentially affecting patient outcomes. With the long-term goal of improving the safety, effectiveness, efficiency and outcomes of LESS, this proposed research targets systematic evaluation of the physical and cognitive differences between CL, unaltered LESS, and LESS with compensatory practices using a simulation-based approach. By assessing and standardizing these compensatory practices, we hypothesize that the relative performance and surgical workload will be equalized between LESS and CL. Conducting this rigorous assessment of LESS, will allow this pioneering approach to be universally adopted and its patient benefits fully realized. It is postulated that LESS will require a greater physical workloa than CL. Similarly, it is hypothesized that unaltered LESS will be cognitively more demanding compared to both CL and LESS with compensatory practices. The expected outcome for the proposed research is to characterize and compare the performance, physical workload, and cognitive workload differences of LESS and CL. These results are expected to have a positive impact by defining the physical and cognitive requirements for LESS and identify best-practices that decrease surgeon fatigue and lead towards the standardization of LESS in order to improve surgeon efficiency and increase patient safety.